Phaeophyphomyces canariensis Sastoque, Stchigel & Cano, 2025

Phaeophyphomyces canariensis Sastoque, Stchigel & Cano , sp. nov. MycoBank MB 850892. Fig. 6 View Fig .

Etymology: The epithet canariensis refers to the Canary Islands, due to the geographic origin of the fungus.

Typus: Spain, Canary Islands, La Palma, Fuencaliente (Los Canarios), from soil near the lighthouse, 15 Jul. 2008, coll. M. Calduch & A.M. Stchigel, isol. A.P. Sastoque (holotype CBS H-25348, culture ex-type FMR 19391 View Materials = CBS 151045 View Materials ) .

On potato dextrose agar after one year at 25 ° C: Mycelium abundant composed of septate, hyaline to reddish brown ( Fig. 6E View Fig ), branched, smooth- to verrucose or tuberculate due to the evagination of the cell wall, thin- to thick-walled, 0.5–1 μm wide hyphae, whose cells swollen through age reaching 4–16 μm wide ( Fig. 6F View Fig ). Phaeophyphomyces canariensis differs from its closest phylogenetic species, Thermocarpiscus australiensis , based on nucleotide sequence alignment of four concatenated loci (deposited in Zenodo, doi: 10.5281/ zenodo.10948357), in the deletions on: ITS positions: 116 (C), 117 (C), 118 (A), 119 (T), 120 (C), 121 (G), 180 (A), 209 (T), 426 (G), 439 (G), 459 (T), 473 (A), 496 (C), 497 (A), 517 (G), 552 (T), 553 (G), 554 (A), 555 (A), 556 (G), 582 (T); LSU positions: 667 (A), 663 (A), 679 (A), 685 (A), 688 (A), 1179 (A); rpb 2 position: 2331 (T); tub 2 positions: 2392 (T), 2393 (T), 2394 (T), 2395 (T), 2396 (T), 2397 (C), 2398 (C), 2399 (G), 2400 (T), 2401 (C), 2402 (C), 2403 (A), 2404 (C), 2405 (C), 2451 (T), 2655 (G), 2656 (G), 2667 (G), 2765 (A), 2769 (C), 2770 (G), 2888 (T), 2926 (A), 2991 (C), 2993 (T), 2994 (G).

Culture characteristics (after 7 d at 25 ° C): Colonies on PCA reaching 2–2.5 mm diam., flat, circular and restricted; margins filamentous and regular; surface grey (5E3), with a sparse, floccose white (5E1) aerial mycelium, which is absent at the margins; soluble pigment absent; reverse pale grey (1B1). Colonies on OA reaching 1.5–2 mm diam., flat, circular, and restricted; margins filamentous and regular; surface bronze (5E5) coloured with a white (5A1) sparse aerial mycelium; soluble pigment absent; reverse bronze (5E5). Colonies on CMA reaching 2–2.5 mm diam., flat and circular; margins filamentous and regular; surface uncoloured with a floccose white (4A1) aerial mycelium at the centre; soluble pigment absent; reverse uncoloured. Colonies on MEA reaching 3–4 mm diam., flat and circular; margins entire and regular, surface brown (5E4), with a white (5A1) floccose aerial mycelium, which is absent at the margins; soluble pigment absent; reverse dark blonde (5D4). Culture iconography after 4 wk of incubation on PCA, OA, CMA and MEA ( Fig. 6A–D View Fig , respectively). Minimum, optimum and maximum temperature of growth on PDA after 7 d: 20 °C, 25 °C and 30 °C, respectively.

Notes: Phaeophyphomyces canariensis was placed in a fully supported clade close to T. australiensis , but as a different genus ( Fig. 1 View Fig ). This fungus lacks fertile structures but is molecularly easily distinguishable from the rest of the Chaetomiaceae based on the sequences of phylogenetically informative molecular markers. Using the BLAST search tool, the closest hits the rpb 2 sequence was Arcopilus megasporus CBS 127650 [GenBank MZ342971 View Materials ; identities = 732/832 (87.98 %), four gaps (0 %)] and T. australiensis CBS 493.74 [GenBank KM655419 View Materials ; identities = 751/857 (87.63 %), no gaps]. Using the tub 2 sequence, it was T. australiensis CBS 493.74 [GenBank MZ343024 View Materials ; identities = 440/549 (80.15 %), 26 gaps (4 %)].